Question

a cube of plastic is 1.20 x 10^-5 km on a side has a mass of 1.70 g. show by calcuations whether this plastic cube will sink or float in pure water

Answer 1

Whether something sinks or floats in water depends on its density. Something with a higher density will sink, while something with a lower density will float. The density of water is 1.00 g/mL. We need to calculate the density of the plastic:

1.20 x 10^-5 km = 1.2 cm
Volume of plastic cube = (1.2 cm)^3 = 1.728 cm^3 = 1.728 mL
Density of plastic = 1.70 g/1.728 mL = 0.984 g/mL

Because the plastic has a lower density than water, it will float.

Answer 2

thank you so much!